On a cloudy morning at the airport in Juba, the capital of Southern Sudan, a long motorcade of white Land Cruisers is lined up on a battered runway, motors idling. Secret Service agents listening stoically to their earpieces, clusters of soldiers in camo fatigues, tall Sudanese dignitaries in dusty suits — we've all been waiting out on the tarmac since well before nine, checking the sky. Jimmy Carter likes to say, "I have a fetish about being late," and even here, halfway across the world, everyone knows that showing up early to see him arrive precisely on schedule is part of the experience, like watching Clinton eat a cheeseburger or Bush clear some brush.

There is also something distinctly Carter about the choice of destination. Southern Sudan is seeking independence from the North, but after five decades of on-again, off-again civil war, the country has been so traumatized by killing, famine, slavery and disease that it can seem like a feral place — a failed state even before it has become a state. Though it is early in the morning and still cool, this is late winter, the dry season in northeast Africa, when temperatures rise through the day past 110 degrees. A faint scent of burning fills the air, and the distant echo of things either being constructed or torn apart; in Juba, a war-smashed city with gutted armored personnel carriers strewn along the White Nile, it's often difficult to tell what is a building site and what is rubble.

A white plane banks out of the clouds, and everyone on the runway immediately stops speaking and watches while it lands and taxis to a halt. The cabin door is flung open and there they are, those iconic images from a thousand newscasts: First the smile, then the wave and the climb down to the tarmac, the dignitaries striding forward for formal greetings — the familiar ritual executed with such precision that it is easy to forget for a moment that Jimmy Carter is not still the American president.

I have come to Sudan to begin a period of months of thinking about Carter. The midterm elections are still nearly a year away, but there is already a public perception in the United States, faint but growing, that the Obama presidency is not going well. As observers assail the president for his scattered ambitions, his lack of a grand vision, his outsider's discomfort with the ways of Washington, his fumbling economic policies, how aloof and detached he seems, his undervaluing politics because substance is more important, his having written too many memoirs, and above all for his supposed lack of toughness, the man he is increasingly compared with is Carter. In Foreign Policy, the writer Walter Russell Mead has published an article called "The Carter Syndrome," in which he warns "the conflicting impulses influencing how this young leader thinks about the world threaten to tear his presidency apart — and, in the worst scenario, turn him into a new Jimmy Carter." Peter Baker, White House correspondent for The New York Times, comes to a similar conclusion. Obama, he observes, seems to be looking more and more to Clinton's presidency as a model, "because, in the end, it's better than being Jimmy Carter."

Carter is the great national sinking feeling. Carter is where you end up when you lose your way. These days, the kindest thing most people have to say about Carter's presidency is that he is the best former president, a compliment that Carter tells me doesn't trouble him — "it does annoy my wife" — but which others in a position to know claim "galls him." What does it say about Carter that Obama kept clear of him during the midterm elections, even as he sent Bill Clinton out to stump for Democrats? Clinton! — who had said all those nasty things about Obama back when Hillary was running against him. Carter is where the danger lurks for Obama. Democrats who voted for change in 2008 thought they were getting FDR for the global age, or JFK with better morals. Now they are more like Democrats in 1978, discovering just how uninspiring an inspired man can be.

As for Republicans, Carter has the same effect on them that George W. Bush has on Democrats: He brings out a kind of sputtering, incoherent rage, infused with a deep tincture of fear. A recent poll of prominent conservative bloggers, who were asked to rank the 25 "worst" figures in American history, placed Carter first on the list, just ahead of Obama. How has it come to this? How has Obama's fragile moment become a reminder of the extent to which Jimmy Carter lost control of his legacy? And who really is Carter anyway?

That has always been the rub, the core elusiveness of the man. It would be hard to find a person of comparable fame and ongoing public presence who has remained more personally remote. In 1976, candidate Carter created the impression of an honest, God-fearing peanut farmer with a loving heart who would be a purgative to American integrity in the troubled aftermath of Watergate and Vietnam. Much of what drew people to him was his smile, the most seductive American politics has ever known. It switched on like a floodlight, an intense glow that lingered, warming people long after he was gone. But four decades later, even those close to Carter are still struggling to understand what's behind that luminous grin. There are people like that, about whom we know many things and yet who seem forever unknowable. For a man who has lived his entire life in politics, this opaqueness can serve a useful purpose. It draws us closer to him, encourages us to fill in the blanks, to see our best selves in him. But if that proves impossible, the ensuing disappointment and frustration can also produce a ferocious backlash, an untethered need to lash out at what we have been denied.

"Carter's always been an enigma," says Jerry Rafshoon, who served as Carter's White House communications director. "The problem is that people can't categorize him, pigeonhole him. Is he liberal? Moderate? Conservative? Tell me the issue! Even then it's complicated. You can't put labels on him. Never could. When he got into office, the liberals were unhappy with him. Conservatives, especially in the South, were unhappy with him: 'He's one of ours and he disappoints us!' I used to hear complaining from all sides. I'm seeing that with Obama now."

The rituals of arriving in a foreign country still give Carter obvious satisfaction. Although he and Rosalynn, his wife of 64 years, are usually inseparable — during his presidency she sat in on his Cabinet meetings — he has come to Juba without her. She had taken ill in Khartoum, their previous stop, and stayed behind to rest up and visit the Nubian pyramids. Carter has been under the weather himself; on the flight to Juba, he later confesses, "I threw up two or three times." But for the most part, long-distance travel affects him as little today as it did when his conveyance was Air Force One, and he traversed the world, impervious to jet lag.

This morning, he's wearing khakis, casual black shoes, a blue shirt and a red tie. In other words, he still dresses like a high school guidance counselor. He shops like one, too. Carter flew to Africa on a supporter's private jet, but he buys his clothes at the Dollar General store back in Plains, Georgia. "Tight as bark on a tree" is Carter's old friend Dot Padgett's cheerful assessment of his Depression-era frugality.

Carter's days rarely involve spontaneity. Through the agency of the Carter Center, the flourishing, action-oriented organization he founded in 1982 to resolve international conflicts, promote democracy and fight disease, he keeps so busy that his calendar is a legendary document covered with transverse lines, abstract art made out of advance planning. Rita Thompson, a volunteer on his 1976 campaign who now serves as a family assistant, says, "He relaxes once a year. The week after Christmas." That's when Carter takes a family trip with his children, grandchildren and great-grandchildren that he organizes right down to the minutes set aside for "free time." To be late for anything on the itinerary is to be left behind, with an exception granted for Rosalynn, whose 57th-birthday present from Carter was a promise to never again nag her about "tardiness." The other 51 weeks, Carter's preferred pace is constant motion, flurrying from briefing to meeting to press conference, maintaining a slam-the-door-and-go tempo that keeps everyone who works for him aware at all times of where the exit signs are.

Although Carter insists that he travels as a private citizen, the truth is that he operates as a foreign service of one, going where he pleases, making his own assessments, issuing statements that can alter the course of world events. The ambiguity of this official-yet-unofficial status has irritated every American president from Reagan on. ("I didn't like it when a certain former president — and it wasn't 41 or 42 — made my life miserable," George W. Bush has complained.) But it's not hard to see why foreign leaders find the time to talk with Carter; a former American president, even one often at odds with his own government, possesses an inevitable patina of power. Up in Khartoum, Carter had met with Omar Al-Bashir, the Northern dictator whose militias have slaughtered millions, to remind him that the Carter Center was organizing impartial observers to monitor this month's highly charged referendum on independent Southern statehood. Now, after meeting with the Southern president, Salva Kiir, Carter climbs into a Land Cruiser and heads off to pursue his other major project in Sudan: curing the great plague caused by a waterborne parasite called the Guinea worm.

Guinea worm has been an excruciating human scourge dating back to biblical times, when it was known as the Fiery Serpent, and is thought to have tormented the followers of Moses. Once someone becomes infected from drinking stagnant water, a white worm as long as three feet forms in the abdomen before slowly emerging through a burning lesion. Although rarely fatal, Guinea worm cripples those infected, leaving them temporarily unable to participate in life and exacerbating their poverty. When Carter left the White House, an estimated 3.5 million people in 20 countries suffered from the disease.

One of the great tensions in Carter is the relationship in him between virtue and ambition; it's often hard to square his public image of piety and good works with his relentless competitive streak. This is a man who, while out turkey hunting, once claimed he could make a better turkey call than a turkey could. Carter's protégé and campaign director, Hamilton Jordan, called his boss "the world's worst loser." Jordan may have had Carter's tennis playing in mind. At the Georgia governor's mansion, there were thorny rose bushes growing alongside the tennis court, and Carter liked working the angles to place shots that produced scarred as well as defeated opponents. In 1986, still smarting from as conspicuous a defeat as this country can provide, Carter was looking to win at something big when he was approached by an old health policy adviser, Dr. Peter Bourne.

Bourne knew he didn't have to convince Carter of the virtues of curing disease. The former president had grown up in rural South Georgia, one of the most backward regions of the United States, where it was routine to see sores on the skin of pellagra-stricken sharecroppers; Carter understood the relationship between stigma and sickness, the circular way one keeps leading to the other. But there are a lot of illnesses in the world that bedevil poor people, and unlike Guinea worm, some of them afflict Americans. So Bourne sold Carter on fighting the Guinea worm by pointing out that only one disease in history has ever been completely eradicated: smallpox. That coup had been less a matter of science than a massive engineering enterprise, a medical Manhattan Project. Guinea worm, Bourne said, could be the world's second eradicated disease. All that would be required for Carter to achieve such a rare and glorious victory was a sustained organizational effort — the kind of undertaking certain to appeal to an engineering graduate, U.S. Naval Academy, Class of '47. With that, Bourne had his man.

The first personal trait most people would think to describe in Carter is motivation, how much stamina he can summon of himself to defeat a problem over a sustained period. His college sport at the Naval Academy was cross-country, and until his knees failed him in his seventies, he continued to run long distances. "I was a fanatic runner," he tells me. "Forty miles a week for a long time." What made Carter well suited to the sport also explains his aptitude for long-term projects, the way patience and impatience play at useful tension in him. He is always thinking about the distant finish. As a politician, Carter seemed to thrive on being underestimated. He was inevitably the long-shot candidate who campaigned so tenaciously that he simply wore down his better-known opponents. (In his 1970 run for Georgia governor, he shook 600,000 hands and visited, he claimed, every factory gate in Georgia.) During his presidency, his greatest achievement was the Camp David Accords, the historic framework for peaceful relations between Israel and Egypt that was negotiated over 12 days in September 1978, and which succeeded only because Carter shuttled back and forth between the Egyptian president Anwar Sadat and the Israeli prime minister Menachem Begin, staying up deep into the night, refusing to allow them to quit, singing Israeli folk songs with Begin's delegation, refereeing moments of stalemate and outrage, inexorably coaxing them toward an agreement. In the end, when Sadat and Begin raised their arms in joint accomplishment, it was Carter's unexpected victory.

It has been the same way with Guinea worm. Today, a quarter-century after Carter took up the cause and began deploying platoons of volunteers across the world, only 1,700 cases of Guinea worm are thought to still exist, most of them somewhere out in the vast Southern Sudan bush. "Village by village, like chewing on a rock, we make progress," is how Carter describes the process. Once I hear him use this phrase, it seems so perfectly to express Carter himself that for a long time afterward, whenever I think of him, I imagine a man with a chunk of shale in his mouth, biting down hard.

Before heading out into the bush to visit a remote village, Carter meets with a group of health officials and volunteers at the U.S. consulate in Juba. Nothing energizes Carter more than a good Guinea-worm meeting, and this one is full of PowerPoint presentations and meticulous reports from in-country. Carter sits at the head of the table, listening to health workers who have emerged from the field, taken long showers and put on their best clothes to meet the former president and describe what they need from him to finish the job. They look like campaign volunteers, and they have the same all-in passion for the cause — they are sure that Guinea worm will be totally eradicated by 2012, if there is no more war in the region. "We will get there!" one of them declares.

The torrent of infrastructure data and case-reduction figures Carter is absorbing brings to mind the president whose appetite for briefing-book minutiae was such that his CIA director Stansfield Turner says he once approached Carter to bring him up to speed on world food supplies, only to discover that his boss had already memorized the figures for wheat production per hectare in places like Afghanistan and India. Donald Hopkins, a leading epidemiologist who helped eliminate smallpox and now directs health programs at the Carter Center, compares the former president to Jack Webb, the relentless detective from the old TV show Dragnet. "Just the facts," Hopkins says. "He wants the bottom line, and you can't bluff him."

Listening to the health workers in Juba, Carter offers praise and encouragement, although in limited doses. He has never been much for approbation. "Every sort of compliment you get from him is hard not to take," is the delicate way that Bert Lance, his closest White House adviser, puts it. Carter's two great mentors in life were his father, a businessman and land owner, and the Navy admiral Hyman Rickover, who created the country's nuclear submarine program and chose Carter to take part in it. Their mutual way of nurturing Carter was not to say anything about his performance unless they found it lacking. Carter's response, according to Rafshoon, was to become a person who is "always wanting to prove it to somebody."

The conference room at the consulate has cold soft drinks and dishes full of fresh macadamia nuts, and the surrounding compound includes a swimming pool where Carter can complete his daily regimen of at least 40 lengths. But atop the exterior walls are spikes of barbed wire, and a sign on the exit gate warns those heading out to vary their transit routes and never to travel without a cellphone. Encountering Carter in such a setting, it is difficult not to think of the Iranian hostage crisis of 1979, the event that abruptly alerted Americans that they were now as vulnerable as everyone else. That November, Islamic students stormed the U.S. Embassy compound in Tehran, holding 52 hostages captive for the final 444 days of Carter's presidency. Carter himself became a prisoner of the predicament, growing so obsessed with the hostages that for months on end he remained in the Oval Office, refusing to light the national Christmas tree or campaign for re-election. His inability to make a band of flag-burning militants in a small nation bend to our will enraged an electorate whose desire to see America as an indefatigable force in the world prevented them from finding virtue in a dogged president whose determination to wait the situation out, in the end, brought every hostage back alive.

At home, Americans were also becoming increasingly familiar with an economic indicator known as the Misery Index. Oil shortages led to an "energy crisis," double-digit inflation and high unemployment. Carter responded by appointing Paul Volcker to lead the Federal Reserve. Volcker, he knew, would raise interest rates, creating a counterbalancing recession. There would be many months of economic pain, and then, well after the presidential election in November 1980, there would be relief. Stuart Eizenstat, who served as Carter's chief domestic policy adviser, remembers him making the Volcker decision. "He said, 'Inflation can't be my legacy. We must choke inflation out. I've tried everything else.' If that's weak and ineffectual, I don't understand the definition. He took the worst medicine. It was like chemotherapy. He hoped it would work. Otherwise comes death. It worked. Volcker rightly gets the economic credit. But Carter should get the political credit."

At the time, many Americans thought the energy crisis was flimflam. With his concerns about excessive consumption, and the perils of relying so heavily on imported oil, Carter was way ahead of his time — talking hybrids to a country not yet sold on seat belts. Carter says he spent more time thinking about energy policy than anything else, investigating alternatives like synthetic fuels, geothermal energy, wind and solar power, tax credits for energy efficiency. His initiatives cut oil imports in half, a trend that was quickly reversed by Reagan. Reducing foreign oil seemed especially crucial to Carter, he says, because scientists had already noticed "the first glimmer of global warming." There is little doubt that the world would be a far better place today if Jimmy Carter's energy programs had lasted.

In July 1979, Carter searched for a way to explain to an Eisenhower generation used to believing they could have it all, that there were limits in life. He scheduled an energy speech. Then, instead of delivering it, he disappeared. "The whole country did a double take," says the Princeton historian Sean Wilentz. "Nobody knew where he was. He canceled the speech. Where'd he go? Nobody knows what's going on. All was quiet. People thought he'd gone crazy."

Carter was at the presidential retreat in Camp David, where he spent days in reflection, weighing what to say to the nation. Then he came down from the Maryland mountaintop, looked into the camera and announced that the country was suffering from a "crisis that strikes at the very heart and soul and spirit of our national will." But America could revive, if it would roll up its sleeves and sacrifice. "I do not promise you that this struggle for freedom will be easy," he said. "What I do promise you is that I will lead our fight."

The speech was a presidential classic because Carter had done that rare thing: He had spoken to Americans like adults, appealing to that cherished Emersonian myth of self-reliance, offering a progressive way to be patriotic. And the country responded. For a moment, Carter's polling soared — until he followed up the speech a few days later by abruptly asking for the resignations of his entire Cabinet.

Looking on at the time, Eizenstat witnessed a display of political ineptitude that seemed "hard to fathom," almost willful, as though Carter was a man determined to emphasize the difficulty of the times at a moment when what people wanted most from him was a diversion from all the hardship — a worthy cause, an uplifting of the heart, maybe even a laugh or two. In storage, Carter located the old "The buck stops here" sign of his favorite president, Harry Truman, and placed it on his own desk in the Oval Office. But Truman played poker and piano, liked sharp haberdashery, and sent off hasty letters defending his daughter's terrible singing. Truman was fun. Carter, like Obama, had campaigned largely on his own personality; he had charm, but he didn't value it. People close to him were always trying to convince you how funny he was, a sure sign that he wasn't really very funny. Carter was the national drudge. "

After three years in office, there was no buoyancy, no optimism," says Eizenstat. "Optimism — the great presidents have it. Clinton had it. Roosevelt and Reagan had it. President Carter, for all his skills, did not. Maybe because he is a realist."

Carter had campaigned as a leader whom Americans could rely on because he was one of them, just folks, a humble, trustworthy and plainspoken man of faith and of the land. But once in the White House, he seemed different, less down home than a little out there. Part of it was his eccentric family. There was his God-loving evangelist sister Ruth, his Hells Angels-loving sister Gloria, his beery brother Billy and his mother, Miss Lillian, "a sight in this world," as they say in Plains, who once reflected on her own four children: "Lillian, you should have stayed a virgin." At the White House, Carter's divorced son Chip could be found up on the roof getting stoned with Willie Nelson, while downstairs daughter Amy read books at the table during state dinners and roller-skated through the White House halls. When family friends Gregg Allman and Cher came to supper, the Carters watched as their guests mistook the contents of the finger bowls for clear soup, eating even the scented geranium leaves floating on the surface. Amid the chaos, Carter himself seemed an alternately stern and bemused figure, busying himself with briefing books while everyone ran wild around him. His coolness to the national press, coupled with media prejudice against Southerners, had primed many journalists to describe him as "un-presidential," and the widely mocked report in 1979 that his fishing boat had been attacked by a fast-swimming "killer" Georgia swamp rabbit only increased public concern that Carter was too weak and too odd for the job.

The following year, voters sent him back to Georgia. "I can't stand here tonight and say it doesn't hurt," he said in his concession speech, with the tinge of embittered vengeance that still resonates to this day. What tends to define that 1980 presidential election now is the landslide margin that ushered in the Reagan Revolution. Yet in the final few days of the campaign, polls projected a vote too close to call. Hendrik Hertzberg, who served as Carter's speechwriter, recalls being on Air Force One the night before the election, when Carter learned from his press secretary Jody Powell and his pollster Pat Caddell that Reagan was going to beat him. "Jody was in Carter's suite, talking to Caddell on the phone. Carter came in and said, 'Who are you talking to?' Jody said, 'Caddell.' He said, 'Oh, let me talk to him.' I saw him crumple, go pale, kind of go sit down on the bed. We all knew to leave. That's when Caddell told him, 'It's gone.'"

Carter hadn't expected to lose, and once he did, he couldn't get used to it, didn't want to get used to it. When I talk with him about the 1980 campaign, he complains that as it approached, "every headline was dealing with the hostage anniversary, not with the election." He also blames the defection of many of his supporters on Ted Kennedy, whom Carter eventually defeated in the primaries. Kennedy, Carter notes, "refused to shake my hand on the convention platform." Then, in a sudden shift, he acknowledges that the divided Democratic Party was "to a major degree my fault. In the 1976 campaign, I'd done much better as an independent, lonely peanut-farmer candidate who'd never been to Washington. Then when I came to Washington as titular head of the Democratic Party, I never acted as titular caretaker or loving proprietor of the Democratic Party." Say what you will about Carter, more than most politicians, he owns his errors.

Still, Carter believes that had the hostages been released before Election Day, he would have won a second term. Nobody then doubted that Carter was a good man. The country could see how he suffered; they had voted for him and, as is the American way with incumbents, they wanted him to succeed. Instead, the hostages remained captive until minutes after Reagan had been sworn into office. In a conversation at the Juba consulate after the Guinea-worm meeting ends, Carter tells me that when he learned the hostages would be released that morning, he telephoned Reagan with the news, but was informed the president-elect was still asleep and could not be disturbed.

"In the last weeks of my administration, the Reagan administration made it clear they didn't want to be involved in the hostage situation," Carter says. "They said I should handle it 100 percent until I left. I wasn't surprised. I wasn't sure we'd have the hostages released during my term. They were in an airplane on a runway waiting to take off. The Iranians decided not to let the plane take off until I was out of office. I know they were waiting two hours until there was a new administration. I hadn't slept in two and a half days. I didn't have any criticism of Reagan. I didn't need his help or his staff's help."

To those who ask Carter what, in retrospect, he would have done differently as president, he always says what he eventually tells me twice: "I'd have sent one more helicopter." He is referring to Operation Eagle Claw, the secret hostage-rescue attempt that was aborted in the Iranian desert amid swirling sandstorms and wrecked Sikorskys. The mission was widely dismissed as a debacle, but Carter still believes it could have succeeded. "It was tangible," he insists. "We had a plan that would have worked." While he admits that the rise of what is now known as Islamic fundamentalism caught him off-guard — "I didn't ascertain the radical nature of the leadership or the people until after the hostages were taken" — he dismisses complaints that he "humiliated America" by refusing to invade Iran. He knew how popular he would have been at home if he flattened Tehran into a Persian carpet. But unwilling to sacrifice so many lives to the nation's wounded pride, he finished out his term as the last American president to keep the country out of war, then returned home to Plains. He says there were no second thoughts: "I've always felt complete equanimity about what we did as president," he tells me. Yet his defeat prompted feelings of "despair and embarrassment and frustration." He also felt uncertain about what he would do with his remaining allotment of years. He was only 56.

Some people who have worked closely with Carter over the years like to play a parlor game in which the object is to think up the ideal job for Jimmy Carter. Popular entries — Supreme Court justice, pope, benevolent Latin American dictator, Saint Peter at the gates — all stress authority and acumen, without much call for compromise or collaboration. If Carter were to play the game, he would say president. For him, what was worse than losing an election was losing a job he loved. So in Georgia, on his mind was finding a way to replicate the armature of the presidency without actually holding it. One asset he had in this pursuit is that a former president possesses tremendous international prestige. Virtually all former presidents had resisted taking advantage. They had made way for the next man, gone off quietly into the back nine, held off from criticizing policies of their successors that differed from their own. Carter decided he would take advantage, he would criticize, he would not make way.

In 1982, the normally sound sleeper woke in the middle of the night and told his wife, in her recounting, "I know what we can do. We can have a place like Camp David." Immediately, they were planning the Carter Center. Describing those rejuvenating days, he says, "What Rosalynn and I wanted to do was fill vacuums, resolve problems others weren't able or willing to do." From the rustic office he converted out of the garage at his house in Plains, he has spent his post-presidency scanning the world for big, unresolved public dilemmas. Once he locates something that intrigues him, he swoops in. By 2002, he had helped to soothe so many political crises — in Korea, Nicaragua, Haiti, Bosnia and the horn of Africa — that he was awarded the Nobel Peace Prize. Accepting the prize in the Oslo city hall, Carter thanked his fellow Georgian Martin Luther King Jr. for making a national political life possible for a white Southerner of his generation. He also described an increasingly dangerous world in which the most serious threat to peace is "the growing chasm between the richest and poorest people on earth." Then he returned home from Norway and got back to the business of killing Guinea worms.

The day after the Guinea-worm meeting in Juba, Carter heads to a remote village in Terekeka County to call attention to the plight of local sufferers. Eradicating the disease, he tells me, is "one of the most gratifying experiences of my life. Some people who've had Guinea worm have never known success." To be cured of such a conspicuous physical humiliation, he adds, is a way to overcome more general feelings of diminishment: "It gives you a new sense of life and personal integrity." It seems significant that Carter now thinks of the humiliated and the diminished as his primary constituents.

The road to Terekeka County is a rutted, two-lane, red-dirt highway back into the Bronze Age. Carter's destination, the village of Molujore, is a scatter of mud huts where the locals herd cattle, drink water from roadside gullies and livestock lagoons, carve tribal hash marks into their faces with knives, and sometimes subsist on edible leaves and the bush rats naked little boys kill with bows and arrows. It's a strenuous place to travel to for a young man, let alone someone who is 86, and for those who live here, life's rigors are many. During the rainy season, there used to be a case of Guinea worm in almost every hut. It was believed by some that you got sick because an ancestor was angry with you. In a nearby village, the headman became so ashamed of his inability to control the spread of the disease that he hung himself. Now, with cases so infrequent, there is concern in Molujore that there will be no sufferers to display to "the president of all white men," whom everyone has heard is coming to see them.

The large crowd that has gathered in a dusty open area long before Carter's scheduled arrival includes people who have walked for many hours. Under a tent, a bishop wearing magenta robes sits near the governor and the village chief in a Panama hat. At the stroke of 9:30, Carter arrives, sporting a big "J.C." belt buckle. Someone has carted in a podium, and Carter steps up to it. He has no planned remarks for an audience whose language he doesn't speak — but, being Carter, he can't resist offering up a few relevant statistics on declining disease incidence. Someone presents him with a bow and quiver, and another man offers him land so he can return and farm ground nuts. This pleases Carter, once he learns that a ground nut is the local term for peanut. "I'm a farmer!" he tells the man. "I still grow ground nuts on my place."

Carter says that he came to Molujore because of God, and that his presence shows God cares about dispossessed people. "Christianity, 'What would Jesus do?' is very motivating for him," says Carter's son, Jack. "What he thinks God wants him to do with his life is a very significant driver in his life. We used to get in lots of arguments over religion. Mom tells me he had a sign over his bunk in the Navy that said "So What!" There was a cynical side to him at some point."

Health officials had been trying hard to find a Guinea-worm sufferer in Molujore for Carter to meet. Their difficulty leads him to exult, "This could very well be the last village!" Finally, he is led down a trail to a man seated in a plastic chair with a vivid red blister on his foot. Efforts are being made to cajole the worm to come out. It turns out a Guinea worm can be as stubborn as a South Georgia turtle. While he waits, Carter asks the man if this is his first worm. "Yes," the man says.

"And the last," Carter tells him. Carter wants to know if the man is a farmer.

After only 90 minutes in Molujore, Carter is on his way back to Juba. None of the villagers have understood anything he said to them, but because of Carter, they saw their governor, the local commissioner and the bishop all for the first time.

Back in Juba, Carter gives a press conference that begins with what amounts to a Guinea-worm stump speech. With the great retail politician's practiced skill for manipulating the vast amounts of empty matter that fill his days, he manages to sound enthusiastic as he brandishes figures and facts he has recited thousands of times before. Every story Carter ever tells me about himself, I have already read elsewhere, but he tells them all with enthusiasm. This leaves me thinking about what it took to be able to shake 600,000 strangers' hands while trying to get elected governor of Georgia, and what it took to keep count. Carter has a similar approach to inscribing the many books he writes, wherein, incidentally, the same personal stories are often recycled. "When the books come out, he loves setting records," says Rafshoon. "He'll say to me, 'You know Borders bookstore in L.A.? I signed 1,500 in two hours!'â€‰" Achsah Nesmith, who was the president's favorite speechwriter, recalls Carter describing "the satisfaction you'd get as a boy at the end of the day when you could look back and see what you'd accomplished, how much of a row got plowed, how many bales got picked. In farming, there's a lot of satisfaction; he could see what got done. You could see what didn't get done, too. In the White House, it's very hard to see what got done. It's much more of a process."

Now, at the press conference, Carter is suddenly saying something that I find surprising: "One of the best friends I ever had was John Garang." Then he adds, "He and I were like brothers." Garang was the president of Southern Sudan and the leader of its rebel movement until he died in a helicopter accident in 2005. The only foreign leader I'd heard described as Carter's true friend was Sadat. It seems hard to envision Carter actually making time for real friendships, let alone a boon one with a martyred Sudanese militant. But Carter is much given to hyperbole, especially in regard to his personal relationships. "There is hardly a foreign leader or a Democratic politician who is not his 'close friend,'â€‰" Elizabeth Drew wrote in The New Yorker in 1980. Hertzberg marvels at the "coolness of Carter's relationships in general and the warmth of his interactions, often with ordinary people, powerless people or powerful people whose power doesn't threaten his power."

When Carter came to Washington, he brought with him a small, intensely loyal coterie of advisers who became known as the Georgians. The closest of them — Jordan, Rafshoon, Eizenstat, Powell, Bert Lance and Frank Moore — were all younger than Carter, and had all helped him gain office by campaigning against so-called Washington-establishment politics. Perhaps he had such faith in his own intelligence that he prized youthful initiative over seasoned dissent. But surrounding himself with younger men from his home state led to a widespread impression that Carter valued personal fealty above experience — the mark of an insecure leader. "It was so ill-advised to staff the White House with friends from Georgia," says Hertzberg. "I fear he was threatened by people too big or smart around him."

Many who come into contact with Carter find him a little cold at the center. Yet the Georgians, like those who work most closely with him at the Carter Center, have remained devoted to him over the years, though always from a distance. "Friends aren't necessary to him," says Moore, who ran 17 states for Carter during the 1976 campaign. "He's content to sit and read with Rosalynn beside him. They're not out of sight of each other much. If they are, he's miserable. I don't mean miserable." He points at my wristwatch, an old one that had belonged to my grandfather. "That watch," he says. "If it's not on your wrist, you know it's missing, right?"

It's difficult for someone as powerful as a president to make friends, but Carter's uniquely insulated nature was with him long before Washington. It cost him in the White House, and it still does. His independence — intellectually and financially — has always been one of his most appealing qualities. The post-political life that Carter has created for himself as a relentless, motivated outsider tackling enormous world problems has provided a template for other eminent men like Bill Clinton and Bill Gates, who also found themselves in need of second acts that could live up to the power and the glory they had known before. But where Clinton and Gates seem restlessly searching for something satisfying to do, Carter gives the impression of being unable to relinquish a position he believes was wrongfully taken from him. This image may be untrue, but the Democratic Party has perpetuated it over the years by refusing to have anything to do with Carter. By treating him like North Korea, the party only hardens his lifelong impulse to go his own way.

Not long after the trip to Sudan, a senior Obama administration official tells me that Carter had recently called the White House to complain that the president and his advisers were not asking for his advice. So far as I can tell, Carter has felt unappreciated by every administration since the Carter administration, leading him to lash out, in turn, at each of them. The Obama official explains that as much as Carter wants to be helpful, people in government are resistant to giving him assignments because he cannot be trusted to follow instructions. "Jimmy Carter doesn't mix well with Washingtonians," the official explains. "Jimmy Carter feels dissed by Washington, and Washington feels that he never accepts guidance."

It seems inevitable that someone who has been the most powerful man in the world isn't likely to take orders well. But the official says it goes beyond that — it cuts to the nature of who Carter is. The former president, he says, doesn't seem to value others in any deep way, except in terms of what they can do for him. "Jimmy Carter is like the man of whom Goethe said, 'He loved humanity but hated people.' Such a strange, driven man. Almost possessed as he plods forward to spread good to the world in accordance with his — or His — plan."

On another evening, at a quiet Washington restaurant, a different senior official in a dark-blue sweater sits across a table from me, reciting some of Carter's most memorable public remarks. "'I've committed adultery in my heart!'" the man says. "'There's a crisis of spirit in our country!' 'I'll never lie to you!' — they're all so admirable!" The man praises Carter's attempts to eliminate Guinea-worm disease, and his work monitoring international elections. "I love the election monitoring!" the man says. He is getting worked up. "When did it become OK to diss Jimmy Carter?" Then he answers his own question: It all comes down to personality. "When someone totally lacks the ability to schmooze, the only way they can motivate collective action is through deals," he says. "Charm, and the willingness to use it, is essential. But his forward motion is such that it seems impossible for him not to see life as a list of to-dos."

Then the man's take on Carter shifts. "The Teddy Kennedy thing!" he exclaims. "If you're Carter, you're thinking, here's this guy, multiple adulterer, drunkard, and he's the keeper of the liberal flame. There's Jimmy Carter, every day he goes and works against the Guinea worm, and nobody in this town wants anything to do with him. People roll their eyes when his name comes up. I'm blown away by his intellectual command and his bluntness and his total lack of schmooze. Some guys are all form, no substance. He's all substance, no form. Turns out each is bad."

Carter is often criticized for his willingness to visit with dictators, thereby, say his critics, legitimizing them. "I meet with who I choose," he says, "and I always give a full report to the U.S. government." Over the years, he has maintained relations with a gallery of tyrants, including the mysterious leaders of North Korea. In 1994, despite concerns from the Clinton administration, Carter accepted an invitation from Kim Il Sung to visit the Great Leader and his ostracized country. That was during a time of heightened international tension over North Korea's incipient nuclear-weapons program. A CNN crew accompanied Carter on the trip, and the images broadcast back to the United States remain stark in the minds of past and present State Department officials. Carter averted a possible war by spontaneously negotiating both a nuclear freeze and a North Korean summit with South Korea — a spectacular piece of diplomatic legerdemain that might have brought Carter acclaim at home, had he not immediately followed it up with live televised statements undermining his own government and contradicting Clinton administration policies. It was an occasion where the craving for credit, an apparent need for validation, tripped up Carter's better judgment. After Carter and Kim's formal work was done, they cruised the Taedong River together on the dictator's yacht, exchanging compliments and hunting stories, toasting one another with costly wines. Most striking was the obvious mutual attraction between Carter and a pariah who killed his own people in forced labor camps — and warmly talked of God and peace to a visiting American.

The North Koreans still like Carter because they feel respected by him. If he criticizes them, he does so in private and is always careful to let them know he chides his own government as well. That's why, last summer, when North Korea agreed to free Aijalon Gomes, an American who had been imprisoned for illegally crossing the border from China, they announced they would hand Gomes over only to Carter. Returning home from Pyongyang, Carter insisted that the North Koreans "really revere me for being the last person who met Kim Il Sung before he passed away." Then he extended his argument, saying, "We meet with some unsavory people, some outcasts . . . but they're the ones who can solve problems." That unsavory people tend first to cause the problems they are then in a position to solve, is a syllogism Carter did not address.

To improve the world, Carter counsels his staff, sometimes you have to hold your nose and tell the Haitian strongman Raoul Cédras how beautiful his wife is, pose for a photograph with genocidal Serbian generals or raise a glass with Kim Il Sung. It's a theory of international relations that reasonable minds can debate. Those who admire Carter's improvised style of post-presidential international relations include Republicans like Colin Powell and Robert Gates. "He gets slammed for chumming around with dictators, trying to win them over," says Hertzberg. "I don't hold that against him at all. He'll do what it takes. He has devoted himself to foreign policy, where you can function as a dictator among other dictators."

Among some foreign-policy people in Washington, the feeling is that Carter spends so much time with dictators because they, in turn, legitimize him — providing a conduit that enables him to remain involved at the highest levels of power. Aside from his entourage of Secret Service agents, Carter displays few other obvious signs of presidential pedigree — but then, he never favored them as president either. In the White House, Carter was famous for eliminating any trappings of the office he considered "ostentatious," a favorite Carter word. "Hail to the Chief" was no longer played; the presidential yacht Sequoia was sold. He preferred to walk softly and carry his own bag, and he still does. Actual power, however, is another matter. By using his ex-presidential cachet to stay in the thick of world events and yet remain accountable to no one, Carter has achieved a post-modern work of self-fashioning: He's still very much in the game, in a way that is unique in American politics.

In Juba, Carter tells me that he first set eyes on John Garang when the Sudanese revolutionary walked into his Bible study class in Plains. "He'd been visiting Fort Benning," Carter recalls. "He had four of his top people with him. We had a long talk. He described the problems of Sudan. That's when I decided to help the South Sudanese. They'd been through a horrendous war — more than 2 million people were killed. He asked me to help negotiate a peace agreement." The president of Kenya set Carter up with a villa in Nairobi, and "we made a lot of progress." But this "wonderful opportunity for success," Carter goes on, was ruined when "unfortunately, President Clinton came into office. He had a very attractive former Rhodes scholar working for him named Susan Rice. She had a fetish against North Sudan. She wanted to destroy North Sudan. This was very frustrating to me."

Carter makes it clear that he thought more highly of the Sudanese rebel than he did of Clinton's emissary. "Garang, I trusted him and he trusted me. There were things he did I didn't like. He was running a revolutionary army. There were uprisings against him. He'd meet me at airports in Entebbe or Khartoum when I couldn't go to the South. We were kind of like political brothers at a distance. When he had a need or I did, it was a matter of mutual trust and dependence. All I wanted was peace."

The next day, I see Carter in action when he meets with the vice president of Southern Sudan, Riek Machar. Carter, who is quietly laying the groundwork for the Carter Center's role as a watchdog in this month's independence vote, jokes and spars with Machar, a former warlord, in an amiable way. Then his tone suddenly hardens, and he confronts the vice president, demanding to know if he is secretly assembling a new private militia.

"No," Machar insists.

"You don't have a militia?" Carter presses.

"No," Machar repeats.

Carter's powerful intelligence is especially well-suited to negotiation. He is skilled at absorbing facts and points of view, organizing the new information on the fly, retrieving what he needs, building it all into neat summaries that advance the dialogue. As the two men speak, with Carter boring in and Machar earnestly responding, it is easy to forget that there are a dozen other people in the room. A kind of political intimacy exists; Carter is putting himself out there for Machar to feel and experience. There is something flattering in the former leader of the free world taking Machar's circumstances so seriously, even though Machar is also simultaneously on the griddle. I'm reminded of something Hertzberg told me about the necessity of dealing with dictators. "When Carter makes nice to a dictator, people say, 'Isn't that awful!' But he was a lot more successful with Sadat than with Begin, because once Sadat decided it was OK, it was OK. Begin was harder to work with because he was the leader of a rambunctious democracy who couldn't deliver the way that Sadat could." Since democracies cannot act with the decisiveness of dictators, the world sometimes needs a man like Jimmy Carter, a democrat with the will of a despot.

People have been critical of Jimmy Carter for many things, but none of the thousands of cuts he has absorbed across his long political life can compare in intensity with the fury that has followed him since the 2006 publication of his book Palestine Peace Not Apartheid. When Hamilton Jordan heard the title, he told friends it was "the worst mistake Carter has made since he left office."

Carter wrote the book because his frequent visits to Palestine convinced him that Gaza is a "tragic area of the world," and that Israel will be increasingly isolated and vulnerable unless it works to create a Palestinian state. Many people share Carter's general views on the conflict — but to those who don't, the use of the word "apartheid" was abhorrent. Because of it, they made him a "whipping boy," in the words of Carter's former national security adviser Zbigniew Brzezinski. In response to those he offended, Carter offered an Al Het, a plea of forgiveness, for allowing what were intended as constructive criticisms to give the appearance of stigmatizing Israel. His overall aim, he says, is to ensure Israel's welfare at a time when its actions are putting it in peril. Still, he tells me, "At this moment, I don't think I'd change the book's title."

What Carter doesn't engage with is how emotional the issue is for many Jews. Throughout his decades of thinking publicly about the subject, he has rarely expressed any sympathy for Israel's tenuous place in the world, and he rarely credits any Israeli motivations beyond aggressive ones. Nor does he talk much about the security risks of suicide bombers or rocket launchers. He believes that the primary reason Israel is able to treat Palestinians as inferior citizens undeserving of the same rights as Israelis is that they have powerful connections in Washington who let them get away with it. In a recent seminar at Emory University, a young man from Syria asked Carter why American presidents never criticize Israel. Carter compared Israel's influence on members of Congress to that of major pharmaceutical companies. "In the U.S. Congress," he said, "it's impossible to achieve balance on Israel."

Back when Carter was president, the issues at impasse in the Middle East — autonomy, land, settlements — were much the same as they are today. He wanted badly to solve the problem once and for all, and he seems to blame Israeli intransigence for still getting in his way. Carter's certainty that he could, if permitted, resolve such an intractable dilemma seems grounded in his growing awareness of his own mortality. The Middle East conflict, says his son Jack, "is the piece of unfinished business he still has hanging over him." When I take this up with Rosalynn, she insists that her husband's motivations on Israel stem from his deeper convictions. "He just doesn't like to see conflict and oppression of people," she says. "It's been with him a long time, not just something that happened. When he does things that make people think he's favoring Palestine over Israel, it's not anything in it except that he thinks all people are entitled to live in peace. He really believes in human rights for all people."

Carter, a man mindful of his reputation, is well aware of just how destructive the controversy has been for him. Sitting with Rosalynn in a Florida hotel room, he discusses the way it has affected his relationship with Obama. Carter considers Obama a fellow outsider and pragmatic centrist. "I feel a lot of compatibility with him," he says. Obama's grass-roots, youth-driven campaign "thrilled" Carter, and the president's speech on race in 2008 left him "overwhelmed with emotion. That was the best speech on the black and white situation I've ever heard." He praises the way Obama has "transformed the image of America around the world — elevated America's status in an almost miraculous way, compared with what he inherited."

Carter wishes the president would keep his enemies closer by reaching out to North Korea, Cuba, Syria and Iran, but he hastens to mute any criticism and strives to keep his distance in a way that I find poignant. "I don't want to stigmatize him," he says. "I never claim that publicly. We feel very close to Obama. I affected my relationship with the Obama campaign because of my Palestinian book. This was evident to me at the Democratic convention. I'm one of two surviving Democratic presidents. I'd been asked to all preceding conventions and made a speech. On this occasion, I was called by the Obama campaign leaders and told that Bill Clinton and I would be asked to make a documentary to be shown for 20 minutes instead of a speech. That suited me fine. Then Rosalynn and I went to the convention. They showed the film. It was four and a half minutes. We went onstage and waved."

At this point, we've been talking for over half an hour, and Rosalynn hasn't said a word. Now she speaks for the first time. "We understood it and anticipated it," she says curtly.

"I didn't," Carter says.

"I did," says his wife, even more curtly.

"I could tell my role was being minimized. I didn't object. I didn't want to hurt Obama. The American Jewish vote is crucial. But that kinda separated us." Since then, he says, "We do our own thing."

Not long after he returned from Sudan, Carter let it be known that he had been kicked around once too often. He sat down at his father's old desk in his office in Plains, where there is a large presidential seal on the wall near a photograph of Hyman Rickover, and wrote a long and forceful letter to Foreign Policy defending himself against Walter Russell Mead's article. As Rosalynn later explains, "If you're not re-elected, you didn't do anything good. And you get tired of listening to it."

In the letter, Carter condemns Mead's essay as "gratuitous and incorrect." He derides the writer's "cute and erroneous oversimplistic distortions." He admits, with typical candor, that the article made him both resentful and aggravated. Then follows a spirited defense of his record and accomplishments. Mead responded sheepishly, calling Carter "a man who is justifiably unhappy that his presidency's complex story is so rarely treated with the respect and sympathy that it deserves."

Upon taking office in 1977, Carter's minimal foreign-policy experience did not stop him from dedicating much of his presidency to foreign policy. The temptation was understandable. To accomplish anything in domestic politics, a president has to persuade Congress to go along with him. Abroad, he is on his own. (This is the reason a recent New York Times headline read "For Obama, Foreign Policy May Offer Avenues for Success.") When I speak about Carter's legacy with a man who has been participating in American policymaking at top levels for a long time, he predicts that Carter's reputation will eventually improve in the hands of historians on the basis of three foreign-policy achievements: the Panama Canal Treaties, which took on a strategically crucial but politically toxic predicament and modernized U.S. relations with its neighbors; normalization of relations with China, which made way for a fruitful, ongoing American dialogue with the world's most populous nation; and the Camp David Accords, which brought lasting peace between Israel and Egypt. All were crucial, forward-looking gestures that anticipated the shifting power structures of the world.

At the Carter Center's annual Winter Weekend fundraiser in Port St. Lucie, Florida, Carter devotes an entire evening to the Panama Canal, which I take in while sitting with his eldest grandson, Jason Carter. There is much gleeful discussion of how politically unpopular the treaties were at the time, how loathed the so-called "give back" was by conservatives like Jesse Helms, how many senators were subsequently voted out of office after Carter persuaded them to "do the right thing." At one point, Carter proclaims, "Of all the diplomatic achievements of the United States of America in the last 60 years, this is the most important." The much-derided handover, he says, promoted peace, human rights and free enterprise. The canal has generated so much income for Panama that it is now the fastest-growing country in the Americas — and an increasingly powerful U.S. ally. All of which proves to Carter that if you "treat a small country with decency and respect, it pays rich dividends for my country." This comment produces a standing ovation from the audience. Carter looks very moved. "That's quintessentially my grandfather," whispers Jason. "Getting choked up about the influence of the Panama Canal treaty!"

What the Panama Canal Treaties and the Camp David Accords have in common is that they required tremendous diplomatic exertion from Carter, if only because they were of such low political priority to everyone else. "There was something more than a desire to lead," says Hertzberg. "That was very strong. But as strong was the self-sacrificial ideal of doing the right thing even if it cost him the presidency. He risked it over and over. He loved thankless tasks like the Panama Canal. It's a perfect Carter achievement. He got absolutely no mileage out of it. It sparked Reagan. Reagan rode it to the election. And yet, by doing it, he avoided a catastrophic, very serious war in Latin America."

When you talk with people like Hertzberg about Carter, it's clear that they think of him as a flawed leader, but such an intelligent, determined, decent and compelling person that they want him to have been a great president. Only 44 men have been president. What was Carter missing that Lincoln and FDR possessed? At the Winter Weekend, I decide to ask Carter what he thinks are the qualities necessary to be a successful president. In the hours I spend with him over the course of five formal interviews and other casual interactions, his answer is the most revealing thing he tells me.

We are sitting with Rosalynn in his suite at the Florida resort. On the table between us, among cookies and a box of chocolates, is the small, worn, leather Bible from which the Carters read aloud to one another every night before bed. It's a Spanish Bible, allowing them the dual opportunity to study a foreign language. No president was ever a more vigilant self-improver than Carter. Across his adult life, he has taken courses in great books, great issues, speed-typing, speed-reading and dancing. While he was running for president, Carter tutored himself for the job by reading books like James David Barber's The Presidential Character. But despite decades of study and preparation, the question about presidential qualities seems to catch him off-guard.

At first, citing Roosevelt during the Great Depression, Carter says, "successful service in a time of crisis." But this isn't answering the question. "I don't draw a distinction between personal attributes and political attributes," he says. "Personal attributes can be described as tenets of major religious faith. I worship the Prince of Peace. All the great religions stand for peace, justice, the alleviation of suffering, telling the truth. Those are all measures of an academic teacher, in business, the medical world."

He pauses. "I'm fumbling around," he concedes. "I don't really know how to define it. I look from a subjective basis. Another measure of success is to get re-elected, no doubt about it."

He doesn't really know. It's an honest admission, but a painful one. The job meant so much to him, yet decades later, he still cannot define it.

"He's an engineer," says Andrew Young, whose loyal support of Carter's political career led the new president to appoint him U.S. ambassador to the United Nations, the first African-American to hold the job. "Engineers will tell you exactly how to build a bridge, but they can't seem to explain why you need this bridge. He's so fact-oriented, so detailed in almost everything." During the 1976 campaign, speechwriter Bob Shrum resigned nine days after going to work for Carter, explaining, "I am not sure what you truly believe in other than yourself." In a devastating essay for The Atlantic Monthly, another Carter speechwriter, James Fallows, described his former boss as someone who awakened every morning "popping with ideas." But Fallows also confessed, "I came to think that Carter believes 50 things but no one thing." Too often in life, what gets you somewhere is exactly what holds you back once you've arrived.

Although Carter is often forced to think about his political career in terms of his 1980 defeat, his victory in 1976 was far more of an accomplishment than Reagan's. It required astonishing conviction and resolve for a peanut-farming, one-term, out-of-office governor from a tiny town of 600 in a small Southern state to become president. "My name is Jimmy Carter and I'm running for president" was his refrain, a signature greeting like "Hello, I'm Johnny Cash" that allowed people without much in common with Carter to believe they had everything in common with him. "He was the most average Joe that has ever been the president," says his grandson Jason. "He wasn't born in a log cabin, but in the modern age. He didn't know anybody!"

When describing his youth in the town of Archery, outside Plains, Carter likes to focus on his barefoot, farm-boy experiences spent in a home without electricity surrounded by black neighbors; the narrative suits his self-presentation as a man of the people fighting against the special interests. But growing up in the poorest part of Depression-era Georgia, his deprivations were relative. His father, Earl, was a prominent farmer and civic leader who, according to Jimmy Carter, Peter Bourne's biography of his old boss, had as many as 260 black sharecroppers and laborers tending his cotton, corn, cane and peanut fields. Earl also owned a commissary, where his workers bought their supplies at inflated prices — a "license to steal," a Carter neighbor told the biographer Kenneth Morris. As Morris writes in Jimmy Carter: American Moralist, "successfully exploiting blacks" created many comforts for Earl Carter and his family. The Carters had a cook, nice cars, a clay tennis court, a pond house with a jukebox, billiards and ping-pong tables, and crystal salt and pepper shakers on their table. "Jimmy Carter's daddy, I knew him before he died," says Bobby Rowan, a former state senator from Enigma, Georgia. "He was a redneck, hard-nosed, hard-driving Southern plantation owner."

Carter's mother, Lillian, provided her son with a different example. She nursed blacks and whites alike, welcomed blacks through the front door, and late in life served as a Peace Corps volunteer in India because, she said, she wanted to help people with dark skin. "His mother, I loved," says Andrew Young. "She was a devout Christian but anti-church. She told me she liked to sit in front of the church on Sunday morning and drink whiskey. She didn't want anybody to think it was tea, so she put a bottle of Jack Daniels out there. She thought church people were hypocrites. She was a feisty person."

In his many memoirs, Carter again and again confronts the unstated problem of describing his segregated youth for a progressive age. During the civil rights movement, his part of Georgia had the reputation of being fiercely resistant to integration. Mostly, Carter says in his writings, he accepted the situation without really thinking about it. In his presidential campaign biography, Why Not the Best?, he calls his father "my best friend." Yet at other times, he portrays his father as a cold, distant, strict, ruthlessly punctual and skilled man of action, a philanderer and an athlete whom Carter never once beat at tennis. "Hot shot" was Earl's skeptical nickname for his eldest son. This father seemed so daunting to Carter that he spent his childhood thinking of ways to please him, to gain the approval of the man "I almost worshipped."

Like every other member of Carter's immediate family, Earl was a heavy smoker who died of cancer. Young says that losing so many family members so early and to such a quick and brutal disease means "Carter lives most of his life as if under a death sentence."

In 1953, as his father lay dying, Carter returned to Plains from the Navy. He learned of Earl's many charitable acts in the community, how "diverse and interesting and valuable a man's life could be." Against Rosalynn's wishes he decided to resign from the Navy, move back home, take over Earl's peanut-processing warehouse and follow in his father's footsteps. Resettled in Plains, he and Rosalynn were quiet progressives in a bitterly racist community. Carter was the only businessman in town who didn't belong to the local White Citizens' Council. When several members came by and offered to pay his dues for him if he'd join, Rosalynn says he told them, "You can flush it down the john for all I care." There are other such stories of Carter standing up to bigotry, and as a white Southerner of his generation running for national office in 1976, Carter used them to persuasive effect. Yet the reality is a bit more complicated.

In 1966, when Carter first ran for governor of Georgia, he lost to Lester Maddox, an ax-handle-wielding segregationist. So Carter took a month off and then immediately resumed campaigning, preparing for 1970. "He spent four years walking across Georgia, studying Georgia," says Bobby Rowan. "Jimmy Carter was very focused. He needed four hours of sleep a day. Tenacious!" This time, his leading rival was Carl Sanders, a respected former governor who had been the most progressive chief executive in Georgia history. To the outrage of those who knew him, Carter ran to the right of Sanders, courting the poor white vote by tearing at "Cufflinks Carl" for being a wealthy insider entitled elitist. The suspicion that Carter was actually wealthier than Sanders, Carter did not address. Carter also resorted to darker tactics. He promised to invite George Wallace, America's most famous segregationist, to Georgia — a gesture that Sanders had declined as governor. "Carter figured out if he was gonna beat Sanders, it would be with the redneck vote," says Rowan. Carter paid his respects to virulent racists like the White Citizens' Council leader Roy Harris, spoke approvingly of the new all-white private schools that were springing up across the Deep South to skirt integration, and was even quoted as praising Lester Maddox.

To Russell Thomas, a Georgian who helped finance Carter's first campaign for governor, all of this was very disillusioning. In 1970, he approached Carter after hearing him make a speech at an all-white country club. "The tone was that he was going hard to the right, trying to get local folks with him," Thomas recalls. "It was too much. I'll never forget, he told me, 'Russell, I looked out and saw you and the president of the college, and I wondered what you two would think.' I said, 'If you only wondered, that answers my question.' Doing what he had to do to get elected," Thomas concludes, "I felt Jimmy was selling us out."

Carter received only seven percent of the black vote in 1970, but he won the primary against Sanders and the general election. Then, when it came time for his inauguration as governor, he did something that changed his life and that of the country. During the campaign, David Rabhan, a wealthy Savannah entrepreneur with close connections to the civil rights movement, had personally flown Carter around Georgia in his Cessna, free of charge. At the end of the campaign, up in the sky, Rabhan remembers that Carter "turned to me and said, 'You've done all this work. What can I do for you?' I said, 'You can say, Now is the time to end racial segregation.'" Carter agreed. Rabhan told him to write it down on an aviator's navigation chart, the only piece of paper in the cockpit. Rabhan says Carter seemed glad to do it, but "it wasn't burning in him like it was in me."

In his inaugural speech, Carter stood up in Atlanta and announced, "I say to you quite frankly that the time for racial discrimination is over." Listening to words of a kind never before publicly spoken by a prominent politician in the South, Rowan says he and many others were "amazed." Lester Maddox later denounced Carter, which led Jody Powell to remark, "Being called a liar by Lester Maddox is like being called ugly by a frog." Up North, Time put Carter on the cover with the headline "Dixie Whistles Different Tune."

Four years later, when Carter ran for president, he made a point of describing his hanging of Martin Luther King Jr.'s portrait in the Georgia Capitol as a "long-overdue action." But during King's lifetime, Carter avoided ever meeting his fellow Georgian, and he did not attend his funeral. Carter now says that one of the chief regrets of his life was never meeting King, but it wouldn't have been difficult to arrange. Both men worked in Atlanta, and once King spent a very public weekend in the Americus jail, eight miles from Plains.

Carter made an early case for his presidential candidacy in 1974, when he gave a speech at the University of Georgia School of Law. Sen. Ted Kennedy spoke before Carter and addressed the current American "malaise." The comments were so close in spirit to what Carter had planned to say that he threw away his prepared text and scribbled a few notes on a scrap of paper. He then delivered an impassioned, largely improvised address rebuking lawyers, lobbyists and other privileged Americans for their failure to ensure that criminals, prisoners, alcoholics, blacks and the poor were being provided justice. The spontaneous speech, all the more potent coming from a white Southerner, had the rawness of revelation. When Hunter S. Thompson described it as a "king hell bastard of a speech" in Rolling Stone, Carter was suddenly a viable option in the wide-open Democratic field seeking the White House.

"I made an extemporaneous, beautiful speech about the fallibilities and injustices of the Georgia judicial system," Carter tells me with blithe immodesty. "It was an extraordinary speech, if I do say."

No one can become president without a tremendous aptitude for politics, and Carter has always been an enormously political man. Perhaps because his own faith and virtue have always been such vital political attributes, he just doesn't like us to think so. This aversion to seeming political, his unwillingness to admit what he plainly is, has undermined the public perception of his strength — and is part of the reason people wrongly believe he is weak. Calibrated to please his two greatest influences, his father and Rickover, men who were impossible to please, there was a slight madness to the myopic way Carter kept his eyes on the political prize. His ambition caused him to miss the seminal, transformative social event of his lifetime. He steered clear of the civil rights movement when it counted, and he played the race card to move ahead. "He's somebody who was willing to dip on the dark side to get elected," says Julian Bond, the former NAACP chairman who served as a state senator in Georgia. "He wanted badly to get elected. This is what he chose. To me, it was an awful thing to do."

Yet Bond and other leaders of the civil rights movement also stress how far Carter has come from his roots. Rep. John Lewis, who led the historic walk across the Edmund Pettus Bridge in Selma, Alabama, back in 1965, believes that Carter evolved as a person when he left behind the brutal realities of his upbringing to run for president. "Jimmy Carter grew up in a setting where segregation and overt racism were the order of the day," Lewis says. "No longer beholden to the voters of South Georgia, he became a free person. He was liberated."

The evolution continued, Lewis says, when Carter left the White House and became one of the strongest and most vocal advocates for the world's poor. "I tell you, Carter has become something he was not as president. He's being true to himself. People should listen to him. He just keeps going. He's like the Energizer Bunny. He's here! He's there! People can't stand it. He feels a sense of calling and mission. I admire that." In the end, black leaders view Carter with the forgiveness that was a trademark of the civil rights movement. In their eyes, he managed to overcome the fear and hatred instilled in white Southerners of his generation, integrating his better self with his very political nature, leaving behind the kind of race-baiting he briefly engaged in to stand up for those in need. As Bond puts it: "A good man had a couple of bad days."

Last May, on a sun-splashed Saturday, three days before his special election for an open seat in the Georgia state senate, Jason Carter was working the crowd at Atlanta's East Lake Farmers Market when the cavalry arrived wearing a huge j.c. belt buckle. It had taken Jimmy Carter a while to convince his grandson to let him help with the campaign. The situation was complicated for Jason, in part because Jewish voters in his district have mixed feelings about Carter. As Carter had joked in an address to the campaign's volunteers, "I'm glad that Jason has finally confessed that I'm his grandfather."

At the farmers market, everyone wants to meet Carter. "Ask all your friends to vote for my grandson," he tells each person he sets eyes on. He also kisses babies, signs books, poses for pictures and talks turkey with the organic turkey lady. "I just killed a big one the other afternoon, I'm sorry to tell you," he says. He doesn't look sorry. As they leave the market, Rosalynn carrying some lettuce and mushrooms she's bought, all three are ready to go house-to-house, ringing doorbells. Should they work as a team so they can visit as they walk, Jason wonders, or spread out? Carter and Rosalynn, veterans of thousands of mornings like this one, don't hesitate: "Spread out!"

After a few unanswered doors, Carter says, "I used to be an expert at this — I've lost my touch!" But then doors begin opening. "Hi, I'm Jimmy Carter," he greets everyone who answers his ring. "I'm campaigning for my grandson. He's a good kid!" At one house, Carter tells the owners, "You know, when I ran for the state senate for the first time, my opponent got many of his votes from the cemetery!" At another, he says, "When I ran for governor, my wife and I shook 600,000 hands in Georgia. We went to every factory. Every Falcons game." As he approaches a third house, Jason calls from across the way, "I already did that house. They're not home."

Inside a Chevron station's minimart, a woman does a double take. "Jimmy Carter! My favorite president!" At a chicken-wings shop, a Korean man working the counter nearly vaults over it as he cries, "God bless you, Jimmy Carter!" Outside a laundry, a woman almost drops her sack of clothes. "President Carter! Oh, I love you. You are so for real." She puts down her bag and gives him a hug. "Thank you for all you've done. You are a blessing in this world. Let me just hug you one more time. Bless you. You're a fighter."

Carter refuses to sign autographs — it takes too much time — but he'll pose for a picture if you're quick. He explains to several people how to work their cameras. The seminars on buttons and lenses are so technically precise that they bring to mind the Carter that Dan Aykroyd captured in his 1977 Saturday Night Live spoof "Ask President Carter," in which Carter expertly assisted random telephone callers with such conundrums as how to fix a clogged Marvex 3000 postal letter sorter and how to ride out an acid trip. ("Peter, what did the acid look like? ... You did some Orange Sunshine, Peter.")

Afterward, back at his house, Jason sits on his front porch with his mother and his father Jack's ex-wife, Judy Langford. With an election coming up on Tuesday, he notes, his grandfather would still have been out there shaking hands. Instead, Jason blows soap bubbles for his children and talks about Carter.

"Nobody wants their president to be a normal guy," he says.

"That's why things that Papaw did, like carrying around his own bag, were true to who he is, but it wasn't who they wanted the president to be," Judy agrees.

Jason brings up a letter Carter once sent to state wildlife authorities. "He confessed that he went over his limit, because he took one shot and two turkeys died! Nobody believes this! 'OK, forgive me, I shot two turkeys in one!'"

Then they fondly discuss how Carter overplays the virtues he discovered in his father at his funeral and how he makes his childhood sound more impoverished than it really was. Rosalynn tweaks him in this way, too. When she hears his stories of praying for an orange for Christmas as a boy, she reminds him that he got a pony. In reply, he tends to say, "That ol' donkey?!" At his Atlanta apartment in the Carter Center, Rosalynn and Carter sleep in a Murphy bed. Judy finds Carter's parsimony amusing. "One day it was raining," she recalls. "Jimmy had no raincoat. Rafshoon gave him his. Jimmy intentionally never gave it back. Rafshoon still finds ways to remind him."

Most of the people close to Carter enjoy lightly chaffing him when he isn't there. Part of it may be that they want to bring a man who is always doing so many benevolent things for far-flung strangers a little closer to them. "At a fundamental level he is supertrue to a powerful belief that you take every opportunity to make a difference and do good," Jason says. "He really has done what he could. It's like today: If we split up, we can do more."

To get from Atlanta to Plains, you drive due southwest past FDR's Little White House, take a left at Columbus and, passing small churches and tumbledown barns, go back in time. The places we associate with presidents often come to embody our national idea of them, from Hyde Park and Independence to Hyannis Port and Hope. Plains, pop. 635, is the same way, with its flags, railroad spur, water tower and single block of brick buildings on Main Street.

In town, there's no mistaking who comes from here. Carter has devoted a lot of his time to ensuring that Plains will not go the disappearing way of so many rural Southern towns, and the community is a monument to Mr. Jimmy. There are places to buy peanuts, four souvenir shops trading in green-and-white memorabilia, a statue of a 13-foot-tall smiling peanut and various restored period landmarks, such as brother Billy's old service station, where you can no longer buy gas — making it more of a Jimmy Carter memorial than intended. Less than a minute in any direction and you are out in the fields where the plants seem to grow right in front of you out of the sunburned dirt. The smallness of the town and the largeness of the land make it as improbable as ever that an American president came from Plains, but it's also easier to stand out in such a place. Everything seems possible when you're the only one in the crowd.

Jason has prepared me for my visit to Plains. "To me, the thing I admire most about my grandfather and grandmother is that they've done everything they can to stay normal people," he told me. "They built their house in the 1960s, and they almost haven't changed a thing. They were superexcited — legitimately excited! — when the Dollar General store opened in Plains. They buy their clothes there."

Then he was talking about Southerners. "The South is the history of my family," he said. "People were superpoor, rebuilding their state after the war, living through extreme poverty, some of which persists. My grandparents, their microwave is from 1985. It goes tick tick tick tick! It takes 12 minutes ticking down to pop popcorn, because why would you buy a new microwave? The point is that nothing is easy, and why should it be?"

The brown-brick, ranch-style house where Jimmy and Rosalynn live is just as Jason described it. Shaded by tall pines, it looks like the sort of suburban residence where you might expect to find a young ophthalmologist and his family. There is a tennis court and an outdoor swimming pool and a carpentry shop. When Carter left the White House, his staff planned to buy him a Jeep, but he let it be known he'd prefer a set of woodworking tools. Carter has since built many of the wooden furnishings, including a handsome four-poster bed for the master bedroom, a coffee table he fashioned out of a livestock trough, and a chess set. His weekend watercolor paintings line the walls, along with a tropical landscape given to him by Fidel Castro. In the kitchen, along with the elderly microwave and Goldwater-era appliances, is a cartoon in which the devil clutching a huge melting snowball stands near Carter, who is holding a "Jimmy Carter for President" sign. Two other men are looking on, and one says, "My money is on the snowball." A president's life encompasses so many elements — especially a president like Carter, who possesses such an urgent, roaming curiosity about how things work. But the house doesn't really reveal the range of Carter's worldly concerns. It suggests that he doesn't want anything around that would distract him from them.

Carter comes to the door in a faded plaid shirt and jeans and escorts me to the not-spacious living room, where he sits under an Ansel Adams photograph. He seems more receptive to company than usual. Rosalynn is away, promoting her new book on mental illness, and there is a bachelor feeling in the house. In the bathroom, the seat is up and the sink is filled with a jumble of pipes and other plumbing apparatus. On an easel is a painting of a church that Carter is working on.

We talk about 1970. With a borrowed automobile, Carter says, "I drove all over Georgia for four years. I'd work all day at the warehouse and on the farm. In the late afternoon, I'd drive all over the state giving speeches" — to the Jaycees, Lions Clubs, Kiwanis. Late at night, driving home, "I'd dictate on a hand-held Dictaphone the names of people I met." Then letters were sent to all of them. "It was rudimentary, but detailed," Carter says of this extraordinary effort. He mentions the 600,000 hands he shook, the 12,000 pamphlets he handed out and the factories he visited — every one in the state. "I ran against former governor Carl Sanders," he says. "An enlightened guy, but I got the conservative vote. The reason I did was because Sanders had challenged Richard Russell, and all the Russell supporters voted for me." Russell was the revered senator from Georgia who for 38 years led the opposition in Congress to ending racial segregation. Carter, in effect, is suggesting that Sanders defeated himself by alienating white conservatives. This is the first time I have heard this explanation for Carter's defeat of Sanders. I ask him about his campaign's race-baiting.

"I was stigmatized by the Atlanta Journal Constitution, which supported Sanders," Carter says. "They published all along that I was racist." Carter tells me that he met with black leaders "frequently and ostentatiously." Then he says, "I would say that nothing I did or said during the campaign, actual quotes or actions, justify any allegation I was soft on the issue of racists." I tell him what David Rabhan had told me about the way Carter initially avoided blacks and later evolved into a person who spoke out against segregation. "I can't dispute that," Carter says. But then he returns to his defense. If the research were done, he insists, investigators would find "nothing to make a supporter of mine flinch or make anybody think that I opposed exactly equal treatment of black people."

I mention that his old supporter Bobby Rowan once described to me the split between the true Jimmy Carter and the Jimmy Carter who did what he thought it took to win. "I always wished I was from Enigma, Georgia!" Carter says, referring to Rowan's hometown. Then he says, "Had it been a reversal of my previous positions, my inaugural speech would have been a dramatic revelation. I don't think anybody was surprised or saw it as a departure from my campaign."

I tell him that Rowan says many people were, in fact, surprised. "Bobby Rowan is an eloquent person," he says. "I wouldn't dispute what he says."

We talk about the South, about listening to dinner-table conversations as a child at the homes of relatives that featured a stream of grievances about the Northern oppression of the South — "My mother was the only one who would defend Abraham Lincoln." He tells of his 1964 speech in the Georgia legislature, in which he called for an end to the "so-called 30 questions" that blacks were required to answer to qualify to vote — "obscure questions nobody could answer," such as the legal intricacies of habeas corpus and the names of Georgia's Supreme Court justices. "Richard Russell told me I was making a serious mistake," Carter recalls. "Obviously, I disagreed." He mentions how difficult it was for Southerners to admit that slavery was the most important issue of the Civil War. Instead "it was just Yankee domination of the South through the federal government at the expense of states' rights. Now, with the Tea Party movement, that same feeling has come back."

The talk turns to his parents. "My daddy was deeply resistant to the government intruding in personal affairs," Carter says. He and Rosalynn inherited his mother's status as "very liberal on the race issue. An expression was used I won't repeat." In Plains, he says, "a lot of our friends disagreed strongly" with his racial views, and some terminated their relationships. He relates his community's experience of segregation to the current situation in the Middle East, where he believes there is "a similar pressure on Jews who don't want to speak against the treatment of Palestinians. Now, increasing numbers are speaking out for a two-state solution."

Then Carter shifts course, implying that American racism was actually worse in the North. He calls the busing riots in Boston during the 1970s "more severe than any riots that took place in Georgia," and mentions that Philadelphia and Chicago were also plagued by racial hatred. In the South, he says, blacks and whites are more "intimately involved" with one another. Carter isn't the first person from the region where slavery, lynching and Jim Crow held sway to want to shift attention to the sins of the Yankees, but it surprises me that he would. As much as he has done to combat suffering in the world, the suffering that took place next door to him remains complicated within him in a way that his books and our conversations make me suspect he hasn't fully sorted out.

It is time for lunch. In the kitchen nook, we sit down on a blue-vinyl-covered bench and hold hands while Carter says a prayer. Then a silent, African-American woman named Mary Fitzpatrick serves pork barbecue sandwiches on sliced whole-wheat bread. Fitzpatrick met Carter when she was assigned to the Georgia governor's mansion as part of a rehabilitation program for criminals. When Carter won her a reprieve from her murder conviction, she became Amy's governess in the White House, and has worked for the family ever since. She is known for never saying a public word about Carter.

Over lunch, we talk about Carter's favorite book, James Agee's Let Us Now Praise Famous Men, the seminal account of white Depression-era sharecroppers in Alabama, which Carter says he loves because it "told accurately what I knew as a child." Carter expresses his dismay at America's harsh immigration policies, the racist treatment of Hispanics and the long-term incarceration of prisoners without trial. He is gearing up for an afternoon of writing and hunting. There are trips in his future! I mention to Carter that just about everyone I have spoken with about him uses the word "driven." He frowns.

"I don't feel driven," he says. "I feel completely relaxed. I have an almost meticulous commitment to orderly events in my life. I can change total attention from one subject to another without interruption. I get a full night's sleep every night and plenty of exercise." If he isn't driven, I ask, would he at least grant that he's competitive? Yes, he happily concedes. And where did that come from? Even more happily, he says, "I don't know!"

He thinks about it. Then he says, "Once I set a goal for myself — be elected, make a living as a businessman, make the best seed peanuts in Georgia, command a submarine — I am able to devote maximum thought process in planning a schedule of action and to act. When I ran for the Georgia senate, it was easy to give up. All the odds were against me succeeding. I would have died first. People would tell me, 'You have no chance to be elected governor or president.' But if I got only two votes, I'm in to stay. I don't mind competition. I actually relish competition. Same thing at the Carter Center. We try things that might succeed. If they don't succeed, that's OK. Some things that look unachievable, we achieve."

One of the consequences of being the kind of person Carter describes — of possessing such a single-minded fixation on taking action — is that a certain level of reflection becomes impossible. Although he plainly chafes at interviews that take away from all the other things he could be doing, once he commits his time he is engaged and generous, and never seems to be holding back. Yet no matter how much he talks about himself, no matter how many memoirs he writes or how many interviews he gives, he still remains the most elusive of our former presidents.

Among the more iconic images of the Obama presidency is a photograph taken in the Oval Office in January 2009. All four ex-presidents stand shoulder-to-shoulder next to Obama — except for Carter, who is off on the end, a foot away from Bill Clinton. He is, in every sense, a man apart. Some interpreted this as deference, Carter's unconscious admission that he did not belong in such company. But in a recent interview, Carter seemed to suggest that the remove was a way of underscoring what he sees as his ongoing, outsize position in world affairs. "I feel that my role as a former president is probably superior to that of other presidents," he said. "We're right in the midst of the constant daily debate."

That proud, boastful explanation is, in effect, the same one Carter has always given for why he, nationally unknown, thought he could be elected president. As governor of Georgia, Carter met just about every prominent Democratic contender and came away feeling he could do better than any of them. He then proceeded to coolly change American politics by insisting that the way to get elected was to run not on policy but on personality, and to seem the American norm rather than exceptional. His anti-Washington, anti-elite, man-of-the-people, outsider approach worked so well that every successful presidential candidate since Carter has sought to replicate it. (The campaign model of Sarah Palin, another tenacious, bestselling former governor with a big smile from a small state, owes more to Carter than any major candidate since Carter.) That this intelligent, principled, dogged man who remains so steely and enigmatic at his center got himself elected president is one amazing American story. That he reinvented a way for a former president to live on in defeat is another. He accomplished both by relentlessly looking forward — as he still does today. In the end, his personal paradoxes and unresolved contradictions are simply left behind by the arrow of his ambition — the ongoing desire to do something more, to go anywhere to stay in the game, to make a lasting difference.